This is where the harmonic balancer comes in. The circular device, made of rubber and metal, is bolted at the front end of the crankshaft to help absorb vibrations. It's usually connected to the crank pulley, which drives accessories like the air conditioner.
Additional costs: Ground water wells can also be tested for radon, then, if needed, can get a water radon mitigation system installed. Installing a water radon mitigation system runs from $1,000-$4,500, and maintenance runs $0 to $150 annually.
1 The EPA's Installation and Operating Cost Table lists how much a radon mitigation system should cost based on the type of foundation.  Operating a radon mitigation system costs from nothing up to $700 per year. Many radon mitigation systems have fans that require continuous electric power that can add to power bills.